Liquid injector with appropriate operating conditions set by selecting displayed image

ABSTRACT

A contrast liquid injector has a controller that calculates a necessary volume of the contrast medium based on a read out necessary dose of effective component per unit weight, weight of the subject, and concentration of the effective component. The injection rate of a base-operation condition is changed based on the calculated necessary volume of the contrast medium, wherein the predetermined injection time is unchanged, for all volumes of the contrast medium, when making the injection pattern, whereby a timing of an optimum concentration of the contrast medium will be substantially unchanged for all volumes of the contrast medium.

The present application is a divisional application of U.S. patentapplication Ser. No. 13/718,359, filed on Dec. 18, 2012, which is acontinuation application of U.S. patent application Ser. No. 10/691,570,filed on Oct. 24, 2003, the entire contents of each of which areincorporated herein by reference. This application also claims priorityto Japanese application 2003-039756, filed Feb. 18, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid injector for injecting aliquid into a subject, and more particularly to a liquid injector forinjecting a liquid into a subject who is to be imaged by an imagingdiagnostic apparatus such as a CT (Computed Tomography) apparatus, anMRI (Magnetic Resonance Imaging) apparatus, an angiography apparatus, orthe like.

2. Description of the Related Art

Presently available imaging diagnostic apparatus for capturingfluoroscopic images of subjects include CT scanners, MRI apparatus, PET(Positron Emission Tomography) apparatus, ultrasonic diagnosticapparatus, angiography apparatus, MRA (MR Angiography) apparatus, andultrasonograph.

When such an imaging diagnostic apparatus is used to capture afluoroscopic image of a subject, it is occasionally practiced to injecta liquid such as a contrast medium or a saline solution into thesubject. There has been put to practical use a liquid injector forautomatically injecting a liquid into a subject. Such a liquid injectorhas a drive motor and a slider mechanism, and employs a liquid syringethat is removably mounted.

The liquid syringe comprises a cylinder and a piston slidably insertedin the cylinder. The cylinder is filled with a liquid such as a contrastmedium or a saline solution to be injected into the subject. The liquidsyringe is connected to the subject by an extension tube and set on aliquid injection mechanism. The liquid injection mechanism individuallyholds the piston and the cylinder and moves them relatively to eachother for injecting a liquid, typically a contrast medium, from theliquid syringe into the subject.

The operator determines the rate at which the contrast medium is to beinjected and the total amount of the contrast medium to be injected, inview of various conditions, and then enters data representing the rateand total amount into the liquid injection mechanism. Based on theentered data, the liquid injection mechanism injects the contrast mediuminto the subject. The injected contrast medium changes the imagecontrast of the subject, allowing the imaging diagnostic apparatus tocapture a good fluoroscopic image of the subject.

Some liquid injectors are capable of injecting a saline solution as wellas a contrast medium into the subject. For operating such a liquidinjector, the operator enters, if desired, an instruction to inject thesaline solution following the completion of the injection of thecontrast medium, together with data representing the rate at which thesaline solution is to be injected and the total amount of the salinesolution to be injected, into the liquid injector.

Based on the entered data, the liquid injector first injects thecontrast medium and then automatically injects the saline solution afterthe contrast medium has been injected. The subsequently injected salinesolution pushes the previously injected contrast medium, reducing theconsumption of the contrast medium, and also reduces artifacts in thecaptured image.

Liquid injectors of the type described above have been devised andapplied for patent by the applicant of the present application (see, forexample, patent documents 1, 2 below).

Patent document 1: Japanese laid-open patent publication No. 2002-11096;

Patent document 2: Japanese laid-open patent publication No.2002-102343.

The above liquid injector is capable of injecting a contrast medium intothe subject in order to change the image contrast of the subject to astate which allows the imaging diagnostic apparatus to capture a goodfluoroscopic image of the subject.

For injecting an appropriate amount of contrast medium at an appropriaterate into the subject, the operator is required to determine the rate atwhich the contrast medium is to be injected and the total amount of thecontrast medium to be injected, in view of various conditions includingan area to be imaged of the subject and the weight of the subject, andenter numerical data representing the rate and the total amount into theliquid injector. This process is too complex for unskilled operators tocarry out easily, and does not prevent inappropriate numerical values tobe entered into the liquid injector.

In particular, since a plurality of different types of contrast mediumscontaining effective components which have different concentrations arenow available on the market, the operator needs to determine and enterthe rate at which the contrast medium is to be injected and the totalamount of the contrast medium to be injected, also in view of the typeof the contrast medium to be used. This situation makes the entire dataentry process more complex, and poses an increased burden on theoperator in determining and entering the above data for both a contrastmedium and a saline solution if the operator is operating a liquidinjector which is capable of injecting both the contrast medium and thesaline solution.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a liquidinjector which allows the operator to inject a contrast medium into asubject through a simple operating process.

According to the present invention, in order to inject at least acontrast medium into a subject whose fluoroscopic image is to becaptured by an imaging diagnostic apparatus, a liquid injector has aliquid injection mechanism, a condition storage means, an image storagemeans, a section display means, a section input means, a regiondisplaying means, region input means, an operation reading means, and aninjection control means.

The condition storage means stores data of operating conditions of theliquid injection mechanism for each of a plurality of regions to beimaged of a human body. The image storage means stores data of schematicimages of a plurality of body sections of the human body and schematicimages of a plurality of regions to be imaged of the human body inassociation with each other. The section display means displays theschematic images of the body sections in the shape of a human body. Thesection input means accepts an input action to select one of thedisplayed schematic images of the body sections. The region displayingmeans displays the schematic image of at least one of the regions to beimaged in relation to the selected schematic image of the body section.The region input means accepts an input action to select the displayedschematic image of at least one of the regions to be imaged. Theoperation reading means reads the data of operating conditionscorresponding to the selected schematic image of at least one of theregions to be imaged. The injection control means controls operation ofthe liquid injection mechanism under the operating conditions whose datahave been read.

When the operator manually selects one of the schematic images of bodysections and then one of the schematic images of regions to be imaged,the liquid injector injects a contrast medium into the subject underoptimum operating conditions for the selected region to be imaged. Thus,the contrast medium can be injected into the subject under optimumconditions through a simple process. As the operator is not required toperform a complex procedure for entering numerical values of aninjection rate and a total amount of contrast medium to be injected, thecontrast medium is prevented from being injected into the subject underinappropriate conditions due to a mistake that the operator mightotherwise make in entering those numerical values.

The various means referred to in the present invention may be arrangedto perform their stated functions, and may be implemented by dedicatedpieces of hardware for performing the functions, data processingapparatus for performing the functions according to computer programs,functions achieved in data processing apparatus according to computerprograms, or combinations thereof.

The various means referred to in the present invention are not requiredto be individually independent entities, and may be arranged such that aplurality of means may be constructed as a single apparatus, a certainmeans may be part of another means, or part of a certain means and partof another means overlap each other.

A computer unit referred to in the present invention may comprise apiece of hardware capable of reading the data of a computer program andperforming a processing operation according to the computer program, andmay comprise a CPU (Central Processing Unit) to which are connectedvarious devices including a ROM (Read Only Memory), a RAM (Random AccessMemory), an I/F (Interface) unit, etc.

According to the present invention, enabling a computer unit to carryout various operations according to a computer program also signifiesenabling the computer unit to control operation of various devices tocarry out various operations. For example, storing various data in acomputer unit may signify enabling a CPU to store various data in aninformation storage medium such as a RAM or the like fixedly mounted inthe computer unit, or enabling a CPU to store various data in aninformation storage medium such as an FD (Flexible Disc-cartridge) orthe like replaceably loaded in the computer unit through an FDD (FDDrive).

An information storage medium referred to in the present invention maycomprise a piece of hardware which stores in advance a computer programfor enabling a computer unit to perform various processing operations.An information storage medium may comprise, for example, a ROM or an HDD(Hard Disc Drive) fixedly mounted in the computer unit, or a CD (CompactDisc)-ROM or an FD replaceably loaded in the computer unit.

The above and other objects, features, and advantages of the presentinvention will become apparent from the following description withreference to the accompanying drawings which illustrate examples of thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a logic structure of a liquid injectoraccording to an embodiment of the present invention;

FIG. 2 is a block diagram of a circuit arrangement of the liquidinjector;

FIG. 3 is a perspective view of the liquid injector, showing the mannerin which liquid syringes are set on an injection head of the liquidinjector;

FIG. 4 is a perspective view of the liquid injector;

FIG. 5 is a perspective view of a CT scanner as an imaging diagnosticapparatus;

FIG. 6 is a schematic front elevational view showing an initialdisplayed image on a touch panel as a display panel;

FIG. 7 is a schematic front elevational view showing a displayed imageat the time a body section is selected;

FIG. 8 is a schematic front elevational view showing a displayed imageat the time a to-be-imaged region is selected;

FIG. 9 is a schematic front elevational view showing a displayed imageat the time various data are entered;

FIG. 10 is a diagram showing a variable pattern of an injection rate asan operating condition;

FIG. 11 is a diagram showing a CT value as it varies with time based onthe variable pattern of the injection rate shown in FIG. 10;

FIG. 12 is a flowchart of a former part of a processing sequence of theliquid injector;

FIG. 13 is a flowchart of a latter part of the processing sequence ofthe liquid injector;

FIGS. 14 a and 14 b are perspective views showing injection headsaccording to modifications of the present invention;

FIG. 15 is a diagram showing a variable pattern of an injection rateaccording to a modification of the present invention;

FIG. 16 is a diagram showing a CT value as it varies with time based onthe variable pattern of the injection rate shown in FIG. 15;

FIG. 17 is a schematic front elevational view showing a displayed imageaccording to a modification of the present invention; and

FIG. 18 is a schematic front elevational view showing a displayed imageaccording to another modification of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A liquid injector according to an embodiment of the present inventionwill be described below with reference to the drawings. As shown in FIG.4, a liquid injector 100 according to an embodiment of the presentinvention has main body 103 mounted on the upper end of stand 102. Mainbody 103 supports thereon console panel 104, touch panel 105 as adisplay panel, and card drive 107 for PC card 106 which serves as aninformation storage medium.

Movable arm 108 is vertically mounted on a side wall of main body 103,and injection head 110 as a cylinder holder is mounted on the upper endof movable arm 108.

As shown in FIG. 3, injection head 110 has two recesses 112 defined as asyringe holding mechanism in an upper surface of cylinder holder 111.Cylinders 201 of liquid syringes 220 are removably held in respectiverecesses 112. Each liquid syringe 220 comprises cylinder 201 and piston202 slidably inserted in cylinder 201.

Two piston actuating mechanisms 120 are disposed respectively behindrecesses 112 in injection head 110 for individually gripping and slidingpistons 202 of syringes 200 that are held in respective recesses 112.

Each of piston actuating mechanisms 120 has drive motor 121 (see FIG. 2)such as an ultrasonic motor or the like as a drive source for slidingpiston 202 back and forth through a screw mechanism (not shown) or thelike.

Piston actuating mechanisms 120 also have respective load cells 122 aspressure-sensitive devices for individually detecting pressures underwhich pistons 202 of syringes 200 are pressed.

Liquid syringe 200 which is filled with a contrast medium as a liquidand another liquid syringe 200 which is filled with a saline solution asanother liquid are set respectively in two recesses 112 in injectionhead 110. Two recesses 112 and two piston actuating mechanisms 120 makeup liquid injection mechanisms including medium injection mechanism 123for injecting a contrast medium into a subject and solution injectionmechanism 124 for injecting a saline solution into a subject.

As shown in FIG. 5, liquid injector 100 is positioned near CT scanner300 which serves as an imaging diagnostic apparatus. Liquid injector 100injects a contrast medium and a saline solution into a subject who is tobe imaged by CT scanner 300.

CT scanner 300 has imaging unit 301 and control unit 302 which isconnected on-line to liquid injector 100.

As shown in FIG. 2, liquid injector 100 has computer unit 130 connectedto drive motors 121 of two syringe actuating mechanisms 120, consolepanel 104, and touch panel 105.

Computer unit 130 comprises a so-called one-chip microcomputer, and haspieces of hardware including CPU (Central Processing Unit) 131, ROM(Read Only Memory) 132, RAM (Random Access Memory) 133, and I/F(Interface) 134.

Computer unit 130 has a suitable computer program installed in the formof firmware in an information storage medium such as ROM 132. CPU 131performs various processing operations according to the installedcomputer program.

By operating according to the installed computer program, computer unit130 logically has various functions as various means which include, asshown in FIG. 1, image storing function 141, section displaying function142, section entering function 143, region displaying function 144,region entering function 146, condition storing function 147, operationreading function 148, body entering function 149, liquid storingfunction 151, liquid displaying function 152, liquid entering function153, liquid reading function 154, operation adjusting function 156,operation displaying function 157, operation entering function 158,injection controlling function 159, pressure detecting function 160,pressure displaying function 162, condition updating function 163, etc.

Storing functions 141, 151, 147 correspond to storage areas set up inRAM 133 for CPU 131 to recognize data stored therein according to thecomputer program. Reading functions 148, 154 correspond to functions ofCPU 131 to read stored data from RAM 133.

Displaying functions 142, 144, 152, 157, 162 correspond to functions ofCPU 131 to display stored data from RAM 133 on touch panel 105. Enteringfunctions 143, 146, 149, 153, 158 correspond to functions of CPU 131 torecognize data based on input actions on touch panel 105.

Image storing function 141 stores data of schematic images of aplurality of body sections of a human body and data of schematic imagesof a number of regions to be imaged in relation to each other. Sectiondisplaying function 142 displays schematic images of body sections whosedata are stored by image storing function 141 in the shape of a humanbody.

Section entering function 143 accepts an input action to select one ofthe body sections displayed by section displaying function 142. Regiondisplaying function 144 displays a schematic image of at least oneregion to be imaged which corresponds to the body section selected bysection entering function 143. Region entering function 146 accepts aninput action to select the region to be imaged whose image has beendisplayed by region displaying function 144.

More specifically, liquid injector 100 defines “head part, chest part,abdomen part, and leg part” as a plurality of body sections, and data ofschematic images corresponding to those body sections are registered inROM 132. When a certain action is performed on liquid injector 100,schematic images of “head part, chest part, abdomen part, and leg part”in association with body shapes are displayed on an upper screen area oftouch panel 105 as shown in FIG. 6.

Data of schematic images of “brain part, jaw part, and neck part” areregistered as a plurality of regions to be imaged in relation to theschematic image of the body section “head part”. Similarly, data ofschematic images of “heart part” and “lung part” are registered inrelation to the schematic image of the body section “chest part”, dataof schematic images of “stomach part, liver part, . . . ” are registeredin relation to the schematic image of the body section “abdomen part”,and data of images of “upper part and lower part” are registered inrelation to the schematic image of the body section “leg part”.

When one of the schematic images of the body sections displayed as ahuman body shape on touch panel 105 is manually acted upon, a schematicimage of a scanner mechanism is displayed above only the schematic imagethat is acted upon, and that schematic image is highlighted with theother schematic images darkened, as shown in FIG. 7.

At the same time, the schematic images of the regions that are relatedto the highlighted image are displayed below the displayed schematicimages of the body sections. When one of the displayed schematic imagesof the related regions is manually acted upon, that schematic image ishighlighted with the other schematic images darkened, as shown in FIG.8.

Condition storing function 147 stores data representative of operatingconditions of medium injection mechanism 123 and solution injectionmechanism 124 for each of the human body regions to be imaged. Morespecifically, since liquid injector 100 according to the presentembodiment injects a contrast medium and then a saline solution into thesubject, the data representative of the operating conditions areestablished in order to interlink injecting operations of mediuminjection mechanism 123 and solution injection mechanism 124.

The data representative of the operating conditions of medium injectionmechanism 123 are established to change the rate at which the contrastmedium is injected, with time according to a variable pattern such thatthe contrast of a fluoroscopic image achieved by the contrast mediumwill approximate an optimum level. The variable pattern is set to anoptimum pattern based on experimental results. For example, as shown inFIG. 10, the variable pattern is set such that the injection rate islinearly reduced for a certain period of time from the start ofinjection, and subsequently kept constant.

Operation reading function 148 reads data of operating conditions forthe region to be imaged which has been selected by region enteringfunction 146 from condition storing function 147. Body entering function149 accepts an input action to enter a body weight as a human body itemrelated to the capturing of a fluoroscopic image, as shown in FIG. 9.

Liquid storing function 151 stores data of the concentration of iodinewhich is an effective component as a liquid item related to thecapturing of a fluoroscopic image, with respect to each of the productnames of a plurality of types of contrast mediums. Specifically, liquidinjector 100 can use a plurality of types of contrast mediums, whichcontain different concentrations of iodine for the respective products.When a contrast medium is injected into a subject and the subject isimaged to capture a fluoroscopic image thereof, since a different iodineconcentration results in a different contrast, liquid injector 100 hasdata of iodine concentrations registered for the respective names ofproducts as contrast mediums.

Liquid displaying function 152 displays the product names of contrastmediums whose data are registered. Liquid entering function 153 acceptsan input action to select one of the types of contrast mediums whichhave been displayed by liquid displaying function 152. Liquid readingfunction 154 reads data of the iodine concentration which corresponds tothe contrast medium selected by liquid entering function 153.

Operation adjusting function 156 corresponds to a function of CPU 131 tocarry out a predetermined processing operation. Specifically, operationadjusting function 156 adjusts operating conditions whose data have beenread by operation reading function 148, depending on the body weightentered by body entering function 149 and the iodine concentration readby liquid reading function 154.

More specifically, liquid injector 100 has registered data of a variablepattern according to which the injection rate varies with time, as anoperating condition for injecting the contrast medium. The variablepattern is set so as to satisfy a predetermined total amount of contrastmedium to be injected.

The data of the total amount of iodine as a contrast medium whichcorresponds to the body weight of the subject is registered as “A(g/Kg)”based on experimental results. If the body weight of the subject isentered as “B(Kg)”, for example, then the total amount of iodine to beinjected which is proportional to the body weight is calculated as“A.times.B(g)”. If the data of the iodine concentration of the contrastmedium is read as “C (g/ml)”, for example, then the total amount of thecontrast medium to be injected which is inversely proportional to, theiodine concentration is calculated as “(A.times.B)C (ml)”. When thetotal amount of the contrast medium to be injected is thus calculated,if the data of the injection rate is registered according to a variablepattern having a waveform as shown in FIG. 10, then the waveform of thevariable pattern is vertically moved while the period of time consumedto inject the contrast medium remains unchanged, so that the areasurrounded by the waveform, the x-axis, and the y-axis corresponds tothe total amount of the contrast medium to be injected.

Operation displaying function 157 displays the total amount of thecontrast medium to be injected which is an operating condition adjustedby operation adjusting function 156. Operation entering function 158accepts a manual input action for correcting the data of the totalamount of the contrast medium to be injected which is displayed byoperation displaying function 157. When the data of the total amount ofthe contrast medium to be injected is corrected by operation enteringfunction 158 and entered, operation adjusting function 156 adjusts thetotal amount of the contrast medium to be injected depending on theentered data.

Injection controlling function 159 corresponds to a function for CPU 131to energize drive motors 121 of medium injection mechanism 123 andsolution injection mechanism 124 depending on the processed data, andcontrols the operation of medium injection mechanism 123 and solutioninjection mechanism 124 under the operating conditions adjusted byoperation adjusting function 156.

Pressure detecting function 161 corresponds to a function for CPU 131 torecognize data of pressures detected by load cells 122 of mediuminjection mechanism 123 and solution injection mechanism 124. Pressuredetecting function 161 detects in real-time the pressures of thecontrast medium and the saline solution which are injected into thesubject. Pressure displaying function 162 generates in real-time data ofa time-dependent pressure graph from the pressures of the contrastmedium and the saline solution which are detected by pressure detectingfunction 161, and displays in real-time the time-dependent pressuregraph.

Condition updating function 163 corresponds to a function for CPU 131 tocontrol operation of card drive 107. When PC card 106 which stores theregistered data of operating conditions is loaded into card drive 107,card drive 107 reads the registered data of operating conditions from PCcard 106, and updates the data of operating conditions in conditionstoring function 147.

While part of the above various functions of liquid injector 100 isaccomplished by pieces of hardware such as console panel 104, they aremainly implemented by CPU 131 as a piece of hardware as it functionsaccording to resources stored in an information storage medium such asROM 132, etc., and the computer program.

Such resources include a data file of schematic images of a plurality ofbody sections of a human being and schematic images of a number ofregions to be imaged in relation to each other, a data file of operatingconditions of medium injection mechanism 123 and solution injectionmechanism 124 for each of the human body regions to be imaged, a datafile of iodine concentrations for the respective names of products ascontrast mediums, etc.

The above computer program is stored in an information storage mediumsuch as RAM 133 or the like as software to be executed by CPU 131 fordisplaying schematic images of a plurality of body sections whose datahave been registered in RAM 133, for example, in the shape of a humanbody on touch panel 105, receiving an input action made on touch panel105 to select one of the displayed body sections, displaying a schematicimage of at least one region to be imaged which corresponds to theselected body section, receiving an input action to select the region tobe imaged whose image has been displayed, reading data of operatingconditions corresponding to the selected body region, receiving an inputaction to enter the body weight, displaying the product names of aplurality of contrast mediums whose data have been registered, receivingan input action to select one of the displayed types of contrastmediums, reading data of an iodine concentration corresponding to theselected type of contrast medium, adjusting the operating conditionswhose data have been read depending on the entered body weight and theiodine concentration whose data have been read, displaying a totalamount of contrast medium to be injected which is represented by theadjusted operating conditions, receiving a manual action to correct thedata of the displayed total amount of contrast medium to be injected,adjusting the total amount of contrast medium to be injected dependingon the input data, controlling operation of medium injection mechanism123 and solution injection mechanism 124 under the adjusted operatingconditions, detecting in real-time with load cell 122 pressures of thecontrast medium and saline solution which are injected into the subjectby medium injection mechanism 123 and solution injection mechanism 124,generating and displaying data of a time-dependent graph of the detectedpressures of the contrast medium and saline solution, reading data ofoperating conditions from PC card 106 loaded in card drive 107 andupdating data of operating conditions in RAM 133.

Operation of the Liquid Injector:

For using liquid injector 100 of the above construction, the operator(not shown) positions liquid injector 100 near imaging unit 301 of CTscanner 300 as shown in FIG. 5. Then, as shown in FIG. 3, the operatorconnects two liquid syringes 200 to the subject (not shown) placed inimaging unit 301 with bifurcated extension tube 210. Cylinders 201 ofliquid syringes 200 are held in respective recesses 122 of injectionhead 110, and pistons 202 are gripped by syringe actuating mechanisms120.

Then, the operator makes an input action on console panel 104 toinstruct liquid injector 100 to start operating. Touch panel 105 thendisplays an initial image on its display screen in step S1 shown in FIG.12. As shown in FIG. 6, the initial image contains various input itemsarranged successively downwardly according to an input sequence. Theinitial image includes in its uppermost portion schematic images of aplurality of body sections in the shape of a human body.

If the operator touches, with a fingertip, one of the schematic imagesof the body sections displayed on touch panel 105 to select the touchedschematic image of the body section in step S2, then, as shown in FIG.7, the selected schematic image of the body section is highlighted withthe other schematic images darkened, and a schematic image of a scannermechanism is also displayed above the selected schematic image of thebody section.

At the same time, schematic images of a plurality of regions to beimaged which are related to the selected body section are read anddisplayed below the displayed schematic images of the body sections insteps S3, S4. If the operator touches one of the schematic images of theregions to select the touched schematic image of the region in step S5,then only the selected schematic image of the region is highlighted withthe other schematic images darkened, as shown in FIG. 8.

When the region to be imaged is thus selected, liquid injector 100 readsdata of operating conditions corresponding to the selected region to beimaged from RAM 133 in step S6, and also reads a default body weight andthe product name of the previously used contrast medium in step S7.

As shown in FIG. 9, the default body weight and the product name of thepreviously used contrast medium are set as data and displayed in stepS8, and the operating conditions are adjusted according to the bodyweight and the product name in step S9. When the operating conditionsare thus adjusted, a total amount of contrast medium to be injected iscalculated and also displayed in step S10.

The operator confirms the body weight, the product name, and the totalamount of contrast medium to be injected which are displayed. If theoperator finds them satisfactory, then the operator touches, with afingertip, an icon “DECIDE” displayed at an upper right corner of thedisplay screen in step S14 shown in FIG. 13. Liquid injector 100 thencontrols operation of medium injection mechanism 123 and solutioninjection mechanism 124 under the adjusted operating conditions toinject the contrast medium and saline solution into the subject in stepS15.

After the operator has confirmed the body weight, the product name, andthe total amount of contrast medium to be injected, if the operatorwants to enter a body weight, then the operator touches, with afingertip, an icon “+1-” displayed to the right of the item “BODYWEIGHT” in step S11 shown in FIG. 12. The displayed numerical value ofthe body weight then changes, and the operating conditions are adjusteddepending on the changed body weight in step S9.

If the operator wants to enter a type of contrast medium, then theoperator touches, with a fingertip, an icon “SELECT” displayed to theright of the item “CONTRAST MEDIUM” in step S12. Then, product names ofcontrast mediums whose data have been registered are displayed on apull-up menu or the like. The operator selects and touches, with afingertip, one of the displayed product names of the contrast mediums.The selected product name of the contrast medium is now set anddisplayed. The data of an iodine concentration of the selected contrastmedium is read, so that the operating conditions are adjusted dependingon the iodine concentration in step S9.

If the operator wants to directly enter a total amount of contrastmedium to be injected, then the operator touches, with a fingertip, anicon “+1-” displayed to the right of the item “PLANNED AMOUNT TO BEINJECTED” in step S13. The displayed numerical value of the total amountof contrast medium to be injected is changed, and the operatingconditions are adjusted depending on the changed total amount ofcontrast medium to be injected in step S9.

After having confirmed the body weight, the product name, and the totalamount of contrast medium to be injected, as described above, theoperator touches, with a fingertip, the icon “DECIDE” displayed at theupper right corner of the display screen in step S14. Liquid injector100 now controls operation of drive motor 121 of medium injectionmechanism 123 under the adjusted operating conditions in step S15.

As shown in FIG. 10, the total amount of contrast medium is injectedinto the subject according to the variable pattern which is set suchthat the injection rate is linearly reduced for a certain period of timefrom the start of injection, and subsequently kept constant. After theinjection of the contrast medium is completed, an amount of salinesolution proportional to the contrast medium is injected into thesubject by solution injection mechanism 124.

While the contrast medium and the saline solution are being injectedinto the subject respectively by medium injection mechanism 123 andsolution injection mechanism 124, the pressures under which the contrastmedium and the saline solution are injected are detected in real-time byrespective load cells 122 in step S16. Data of a time-dependent graph ofthe detected pressures is generated in real-time in step S17, and thetime-dependent graph is displayed on touch panel 105 in step S18.

During the above injection process in steps S15 through S18, if amalfunction is detected based on the injection pressures in step S19,then an error is displayed as a guidance image on touch panel 105 instep S20, and the injection process is interrupted in step S22.

If the operator makes an input action on touch panel 105 to interruptthe injection process in step S21, then the injection process is alsointerrupted in step S22. After liquid injector 100 has injected thetotal amounts of contrast medium and saline solution according to theoperating conditions in step S23, liquid injector 100 finishes theinjection process, and returns to its initial state in step S24.

While liquid injector 100 is not carrying out the above injectionprocess, the operator may load PC card 106 into card drive 107 and makea certain action to download operating conditions from PC card 106 intoRAM 133.

Advantages of the Liquid Injector:

Liquid injector 100 displays on its touch panel 105 schematic images ofa plurality of body sections in the shape of a human body. When theoperator manually touches and selects one of the schematic images of thebody sections, schematic images of a plurality of regions to be imagedwhich are related to the selected body section are displayed. When theoperator manually touches and selects one of the schematic images of theregions to be imaged, data of operation conditions corresponding to theselected region are read, and medium injection mechanism 123 andsolution injection mechanism 124 are controlled in operation under theoperating conditions.

Consequently, a contrast medium can be injected into the subject underoptimum conditions through a highly simple process. As the operator isnot required to perform a complex procedure for entering numericalvalues of an injection rate and a total amount of contrast medium to beinjected, the contrast medium is prevented from being injected into thesubject under inappropriate conditions due to a mistake that theoperator might otherwise make in entering those numerical values.

Since liquid injector 100 displays schematic images of a plurality ofbody sections in the shape of a human body, the operator is allowed toselect any of the body sections easily and reliably. Because schematicimages of body sections and regions to be imaged are displayed on touchpanel 105 and can directly be manually acted upon, they can be touchedand selected easily and reliably.

With liquid injector 100, medium injection mechanism 123 and solutioninjection mechanism 124 are operated to inject a contrast medium and asaline solution into the subject. Inasmuch as medium injection mechanism123 and solution injection mechanism 124 are automatically interlinkedunder operating conditions, the contrast medium and the saline solutioncan be injected into the subject in interlinked relation to each otherwithout the need for a complex control process.

Liquid injector 100 changes the rate at which the contrast medium isinjected with time according to a variable pattern. Therefore, liquidinjector 100 allows CT scanner 300 to keep a CT value at a level whichapproximates an optimum value and hence to capture optimum fluoroscopicimages. Since the amount of contrast medium used is held to a minimumrequired, the contrast medium can be saved, and contributions can bemade to the subject's health.

When an experiment was made in which a contrast medium was injected intothe subject according to a variable pattern such that the injection ratewas linearly reduced for a certain period of time from the start ofinjection, and subsequently kept constant, as shown in FIG. 10, it wasconfirmed that a CT value approximating an optimum value was maintainedfor a long period of time, as shown in FIG. 11.

The above variable pattern differs from region to region to be imaged,and it would need a tedious and time-consuming process to set andmanipulate such different variable patterns. However, liquid injector100 allows the operator to set an appropriate variable pattern simply byselecting a schematic image of a body section and then a schematic imageof a region to be imaged. Therefore, liquid injector 100 can carry out atedious and time-consuming process based on simple actions on the partof the operator.

While liquid injector 100 is injecting a contrast medium and a salinesolution into the subject, liquid injector 100 detects the pressuresunder which the contrast medium and the saline solution are injected anddisplays the detected pressures as a graph on touch panel 105. Theoperator can thus visually confirm changes in the pressures under whichthe contrast medium and the saline solution are injected in real-time.

When the operator enters the weight of the subject and the type of thecontrast medium used into liquid injector 100, liquid injector 100adjusts the operating conditions depending on the weight of the subjectand the type of the contrast medium used. Therefore, the contrast mediumcan be injected into the subject under better conditions. Furthermore,inasmuch as the total amount of contrast medium to be injected which isadjusted as an operating condition is displayed, the operator can startinjecting the contrast medium after having confirmed the total amount ofcontrast medium to be injected. In addition, the operator can directlyadjust the total amount of contrast medium to be injected if desired.

When a schematic image of a region to be imaged is selected, liquidinjector 100 automatically sets data of a default body weight and theproduct name of the previously used contrast medium. If a contrastmedium which is the same as the previously used contrast medium is to beinjected into a subject who has an average body frame, then the operatoris only required to select schematic images of a body section and aregion to be imaged, and hence finds the entire setting process quitesimple.

Since liquid injector 100 can have operating conditions downloaded fromPC card 106, operating conditions of liquid injector 100 can be updatedsimply and reliably when a new product of contrast medium is sold.

Modifications of the Liquid Injector:

The present invention is not limited to the above embodiment, butvarious changes or modifications may be made therein without departingfrom the scope of the invention. For example, although liquid injector100 according to the above embodiment has medium injection mechanism 123and solution injection mechanism 124 which serve as liquid injectionmechanisms for injecting a contrast medium and a saline solution, thepresent invention is also applicable to a liquid injector having asingle liquid injection mechanism for injecting a contrast medium only.

In the above embodiment, a contrast medium and a saline solution areinjected in interlinked relation to each other according to operatingconditions. Such operating conditions may be set as various data ifdesired. For example, in order to confirm the connection of extensiontube 210, it has been customary to carry out a test injection sessionfor injecting a contrast medium prior to a main injection session, andsuch a test injection session may be carried out according to operatingconditions.

As disclosed in Japanese patent application No. 2002-363675, it ispossible to dilute a contrast medium with a saline solution and injectthe diluted contrast medium according to operating conditions. Since anappropriate iodine concentration differs from region to region to beimaged, it has been the conventional practice to replace the contrastmedium each time a different region is to be imaged. According to theabove embodiment, however, when data of regions to be imaged and typesof contrast mediums are entered into liquid injector 100, data ofoperating conditions are set for appropriately diluting contrast mediumswith a saline solution for corresponding regions to be imaged.Therefore, if a contrast medium of high concentration is loaded,together with a saline solution, in liquid injector 100, then it ispossible to provide various contrast ratios for various regions to beimaged and capture images of those regions without the need forreplacing the loaded contrast medium. The operator thus finds itpossible to operate liquid injector 100 with a reduced burden.

Since the iodine concentration can freely be varied by diluting thecontrast medium with the saline solution, a contrast medium with aniodine concentration that is not commercially available can be injectedinto the subject. Though it would be tedious and time-consuming for theoperator to dilute the contrast medium manually, liquid injector 100allows the contrast medium to be diluted appropriately according tooperating conditions which can simply be selected.

In the above embodiment, touch panel 105 displays a default numericalvalue of body weight, and allows the operator to increase or reduce thedefault numerical value by touching the associated icon for therebyentering a desired body weight. However, it is possible for the operatorto enter a numerical value of body weight directly with a ten-key pad(not shown), or for touch panel 105 to display body weight ranges of 10kg or less, 10-20 kg, etc., for the operator to choose from.

As disclosed in Japanese patent application No. 2002-363675, if amedical record of the subject is available as electronic data, then thebody weight of the subject can be read from the medical record of thesubject. For example, an information storage medium such as PC card 106which stores data of an electronic medical record of a subject may beprepared, and the body weight of the subject may be downloaded from theinformation storage medium into liquid injector 100.

Alternatively, liquid injector 100 may be connected on-line to anexternal database server (not shown) which stores data of electronicrecords of subjects, and the body weight of a desired subject may bedownloaded from the database server into liquid injector 100.

An electronic body weight meter (not shown) may be connected on-line toliquid injector 100, and the body weight of a subject may be measured inreal-time by the electronic body weight meter and the data thereof maybe entered into liquid injector 100. Alternatively, since CT scanner 300has a bed for supporting the subject thereon, the body weight of thesubject may be measured using the bed and the data thereof may beentered into liquid injector 100.

In the above embodiment, the data of a body weight is entered intoliquid injector 100 as a body item about the body of a human being whosefluoroscopic image is to be captured. However, a body shape, an age, agender, or the like may be entered as such a body item. As a result ofvarious experiments conducted by the present applicant, it has beenconfirmed that a body item which greatly affects the capture of afluoroscopic image of a human being is a body weight only. Therefore, itis meaningful to use only a body weight as a body item to be enteredinto liquid injector 100.

In the above embodiment, the product names of a plurality of contrastmediums are displayed for the operator to choose from, and the data ofan iodine concentration of the selected product name is read. However,it is also possible to display a plurality of iodine concentrations forthe operator to choose from, or to allow the operator to enter an iodineconcentration directly with a ten-key pad, for example.

In the above embodiment, the data of operating conditions registered foreach region to be imaged are adjusted depending on the body weight andiodine concentration that have been entered. However, the data ofoperating conditions may be registered for a plurality of body weightzones and iodine concentrations, and the data of operating conditionsmay be selectively read depending on the body weight zone and iodineconcentration that have been entered.

Liquid injector 100 according to the present embodiment may be used incombination with a variety of types of CT scanners 300. CT scanners 300of different types have respective imaging rates as an imaging itemwhich differs from product to product. To cope with such different CTscanners 300, the data of operating conditions may be registered inliquid injector 100 for respective types and imaging rates of CTscanners 300, the data of the types and imaging rates of CT scanners 300may be displayed for the operator to choose from, and the data ofoperating conditions corresponding to the selected type and imaging ratemay be read.

The data of the types and imaging rates of CT scanners 300 may bedisplayed for the operator to choose from, and the data of operatingconditions corresponding to the selected type and imaging rate may beadjusted. The data of the type and imaging rate of CT scanner 300 may beentered from CT scanner 300 or an information storage medium into liquidinjector 100, and the data of corresponding operating conditions may beread or adjusted.

In the above embodiment, operating conditions are downloaded from PCcard 106 as an information storage medium into liquid injector 100.Various products may be used as such an information storage medium.Liquid injector 100 may read data from loaded PC card 106 in real-timewithout copying the data from PC card 106 to RAM 133. Alternatively, thedata of operating conditions may be registered in an external databaseserver, and liquid injector 100 may download the data of operatingconditions on-line from the external database server.

In the above embodiment, liquid injector 100 updates the data ofoperating conditions stored in RAM 133 by downloading the data ofoperating conditions from PC card 106. However, liquid injector 100 maydisplay the data of operating conditions read from RAM 133 on touchpanel 105, and the operator may manually correct the displayed data toupdate the data of operating conditions.

In the above embodiment, touch panel 105 is mounted on the upper surfaceof main body 103 of liquid injector 100, and injection head 110 ismounted on the upper end of movable arm 106 which is vertically mountedon the side wall of main body 103. However, as shown in FIGS. 14 a and14 b, touch panel 105 may directly be connected to injection head 110parallel thereto.

In FIGS. 14 a and 14 b, since touch panel 105 is positioned adjacent tomedium injection mechanism 123 and solution injection mechanism 124, theoperator can directly and easily recognize the pressures under which thecontrast medium and the saline solution are injected by medium injectionmechanism 123 and solution injection mechanism 124 when a graph of thepressures is displayed on touch panel 105.

In the above embodiment, the pressures under which the contrast mediumand the saline solution are injected into the subject are calculatedfrom the pressures by which pistons 202 of liquid syringes 200 arepressed. However, the pressures under which the contrast medium and thesaline solution are injected into the subject may directly be detectedby pressure-sensitive devices which may be placed in liquid syringes 200or extension tube 210.

In the above embodiment, it has been assumed for the sake of brevitythat the pressures under which the contrast medium and the salinesolution are injected into the subject are simply calculated from thepressures by which pistons 202 of liquid syringes 200 are pressed. Inreality, liquid syringes 200 are presently commercially available invarious sizes, and pistons 202 thereof have various end areas.

The pressures under which the contrast medium and the saline solutionare injected depend on both the pressures by which pistons 202 arepressed and the end areas of pistons 202. Consequently, if liquidinjector 100 employs liquid syringes 200 of various sizes, then the dataof end areas of pistons 202 for the various sizes of liquid syringes 200may be registered, and when the type of liquid syringe 200 used isentered, the data of the end area of corresponding piston 202 may beread.

It is possible to judge the type of the contrast medium contained inliquid syringe 200 set on injection head 110 for thereby dispensing withinput actions to enter types of contrast mediums used and hence reducingthe burden on the operator. To judge the type of the contrast medium, asdisclosed in Japanese patent application No. 2002-021762, injection head110 may be arranged to acquire identification data of various liquidsyringes 200 and the contrast mediums from cylinder adapters (not shown)when liquid syringes 200 are set on injection head 110 by the cylinderadapters.

Alternatively, the data of the types of contrast mediums may be encodedon bar codes (not shown) applied to various liquid syringes 200, and maythen be read by injection head 110 for allowing liquid injector 100 toacquire identification data of the contrast mediums.

In the above embodiment, the data of the previously injected contrastmedium is saved and used dispensing with unnecessary input actionsunless the contrast medium is changed. In addition, the data of thepreviously imaged region, for example, may also be saved. Specifically,liquid injector 100 may be used in such environments that it capturesimages of the brain part only for brain surgery applications and imagesof the heart part only for heart surgery applications. In thoseenvironments, the data of the previously imaged region is saved and useddispensing with unnecessary input actions unless the region to be imagedis changed.

In the above embodiment, the injection of liquids with liquid injector100 and the capture of images with CT scanner 300 are individuallymanually controlled and carried out. However, liquid injector 100 and CTscanner 300 may communicate with each other for their operations areinterlinked.

For example, when the schematic image of a region to be imaged isentered into liquid injector 100, the data of the region to be imagedmay be set in CT scanner 300 in response to the entry of the schematicimage into liquid injector 100. In this manner, the burden on theoperator to operate liquid injector 100 and CT scanner 300 is lessened.

The period of time consumed until the contrast medium reaches a regionto be imaged may be set as data in operating conditions, and the regionmay start being imaged after elapse of a given period of time from thestart of injection of the contrast medium under the operating conditionsthus set. The period of time consumed until the contrast medium reachesa region to be imaged may be measured in a test injection session byliquid injector 100, and set as data in operating conditions. In thiscase, the period of time can reliably be set as data in operatingconditions.

In the above embodiment, FIG. 10 shows by way of example the variablepattern which is set such that the injection rate is linearly reducedfor a certain period of time from the start of injection, andsubsequently kept constant. However, the data of various variablepatterns may be set based on experimental results, and the injectionrate is nonlinearly changed.

When the inventor conducted an experiment in which a contrast medium wasinjected into the subject according to a variable pattern such that theinjection rate was linearly reduced for a certain period of time fromthe start of injection, and subsequently linearly increased, as shown inFIG. 15, it was confirmed that a CT value approximating an optimum valuewas maintained for a long period of time, as shown in FIG. 16.

In the above embodiment, schematic images of body sections in the shapeof a human body as seen from a lateral side thereof are displayedhorizontally in the uppermost portion of the displayed image. However,as shown in FIG. 17, schematic images of body sections in the shape of ahuman body may be displayed as seen from a front side thereof and may bedisplayed vertically in a side uppermost portion of the displayed image.The input items should be arranged successively downwardly according toan input sequence as they are effective to make it easy for the operatorto understand the input sequence intuitively.

In the above embodiment, the operator is required to select a region tobe imaged and enter a body weight and a contrast medium type. However,as shown in FIG. 18, liquid injector 100 may be arranged to set the dataof an injection rate, a total amount of contrast medium to be injected,and a time for which the contrast medium is to be injected, without theneed for entering a body weight and a contrast medium type, once theoperator selects a region to be imaged.

The above arrangement is particularly effective if a contrast mediumtype is available in one type only, if a plurality of contrast mediumsis available with no essential difference existing therebetween, if acontrast medium to be used is specified and its data are registered inadvance, or if only subjects having a standard body weight are to beimaged. In these instances, the burden on the operator is furtherreduced.

In the above embodiment, CT scanner 300 is used as an imaging diagnosticapparatus, and liquid injector 100 injects a contrast medium for usetherewith into subjects. However, an MIR apparatus or a PET apparatusmay be used as an imaging diagnostic apparatus, and liquid injector 100may inject a contrast medium for use therewith into subjects.

In the above embodiment, CPU 131 operates according to the computerprogram stored in RAM 133 to logically perform the various functions asthe various means of liquid injector 100. However, the above functionsmay be implemented by pieces of hardware, or some of the functions maybe stored as software in RAM 133 and the others implemented by pieces ofhardware.

While preferred embodiments of the present invention have been describedusing specific terms, such description is for illustrative purposesonly, and it is to be understood that changes and variations may be madewithout departing from the spirit or scope of the following claims.

1. A liquid injector for injecting at least a contrast medium into asubject whose fluoroscopic image is to be captured by an imagingdiagnostic apparatus, wherein said contrast medium is available in aplurality of types having different concentrations of an effectivecomponent, said liquid injector comprising: a liquid injection mechanismfor injecting at least said contrast medium into said subject; controlmeans for controlling operation of said liquid injection mechanism underoperating conditions whose data have been read; a display/touch paneladapted to display icons for selecting body area, and to accept aselection of one of said icons when one of the displayed icons isselected, said control means is configured: (i) to read out abase-operation condition including data of: a predetermined injectiontime for injection corresponding to the selected body area, a necessarydose of an effective component of the contrast medium per unit weight ofthe subject corresponding to the selected body area, a concentration ofthe effective component, and an injection rate, (ii) to calculate anecessary volume of the contrast medium based on the read out necessarydose of effective component per unit weight, weight of the subject, andconcentration of the effective component, (iii) to make an injectionpattern based on the calculated necessary volume of the contrast mediumand the base-operation condition, and (iv) to perform the injection ofcontrast medium based on the injection pattern by controlling theoperation of said liquid injection mechanism, wherein the injection rateof the base-operation condition is changed based on the calculatednecessary volume of the contrast medium, and wherein the predeterminedinjection time is unchanged, for all volumes of the contrast medium,when making the injection pattern, whereby a timing of an optimumconcentration of the contrast medium will be substantially unchanged forall volumes of the contrast medium.
 2. A liquid injector according toclaim 1, wherein the display panel is adapted to display a plurality ofbody sections in schematic images of a shape of a human body, and toaccept a selection of one of said body sections when one of thedisplayed body sections is selected, and wherein, when one of the bodysections is selected, the display panel is further adapted to display atleast one of a plurality of regions to be imaged of the human body inschematic images of shapes of the regions, and to accept a selection ofone of said regions to be imaged when one of displayed regions to beimaged is selected.
 3. A liquid injector according to claim 2, whereinthe display panel displays the body sections in a shape of ahorizontally displayed human body image.
 4. A liquid injector accordingto claim 2, wherein the display panel displays the body sections in ashape of a vertically displayed human body image.
 5. A liquid injectoraccording to claim 1, further comprising: means for displaying bodyitems relating to subject's body; means for accepting an input ofselecting one of the body items; and means for adjusting the operatingconditions based on the selected body item.
 6. A liquid injectoraccording to claim 5, wherein the body item includes at least one of abody weight, body shape, age and gender.
 7. A liquid injector accordingto claim 1, further comprising a unit for reading data of a subject'sbody weight from an external database server.
 8. A liquid injectoraccording to claim 1, further comprising a unit for reading data of asubject's body weight from an information storage medium.
 9. A liquidinjector according to claim 1, further comprising a unit for readingdata of a subject's body weight from an electronic scale to measureweight.
 10. A liquid injector according to claim 1, wherein the displaypanel displays a predetermined body weight as a default value.
 11. Aliquid injector according to claim 1, further comprising: means fordetecting in real-time a pressure of the contrast medium duringinjection, and means for displaying in real-time the detected pressureon the display panel.
 12. A liquid injector according to claim 1,wherein the liquid injection mechanism comprises a contrast mediuminjection mechanism for injecting a contrast medium and a solutioninjection mechanism for injecting a saline solution, said base-operationcondition comprises a pattern wherein the injection of the contrastmedium and the injection of the saline solution are interlinked for theselected area to be imaged, and said control means is for reading outthe base-operation, and for performing the interlinked injection of saidcontrast medium and said saline solution by controlling said contrastmedium mechanism and said solution injection mechanism.
 13. A liquidinjector according to claim 1, further comprising an injection head anda console.
 14. A liquid injector according to claim 13, wherein theinjection head is provided with a display panel.